Webmasters trying to utilize the form received a "oops, not working" error when they tried to access it. Google partners with StopBadware.org for malware detection and handling. Reportedly, www.stopbadware.org was also having issues at the same time and they were reporting errors that read "500 - Internal Server Error" throughout the day.
Googler, JohnMu, suggested that webmasters can also submit Malware Reviews directly at StopBadware.org at this form, if the Google form does not work.
The Google form is now working, about 24 hours later. I am actually amazed at the number of complaints about the form not working. It seems like the form is used more often then I would have thought. JohnMu said, if you submitted a review, they likely re-submitted it anyway, but double check to be sure. He said:
We went through all the failed requests and submitted them again, but you may want to double-check your sites just to be sure.
Here is a picture of the malware review form:
Forum discussion at Google Groups.